Trapdoor Expansion

by Purple Johnson Blimp Situation



Unfortunately, the A500 does NOT come with a Hard Disk controller, so you cannot just plug in any IDE or SCSI disk unless you have one.
The original hard disk was the A590 by Commodore which included a 20Mb XT Hard disk, this can be upgraded to a large SCSI hard disk later. This device plugs into the Expansion port on the left side of the A500. Other manufacturers including GVP, Dataflyer, have developed a hard disk controller and disk combination for both SCSI and IDE types of hard disk. As for hard disk sizes, you can have up to 4Gb Drives but beyond that, the file system needs to be upgraded to utilise beyond the 32 bit limit of Workbench otherwise the data on the hard drive can become corrupted. Installing Kickstart 3.1 and Workbench 3.1 plus a file system such as SFS or PFS can overcome this limitation.

Installing Workbench onto a Hard Disk:

To install Workbench 1.3 onto a Hard disk, you need to partition and format the hard disk. The standard tool is HDToolbox, but it is not always supplied, see the equivalent tools and documentation for your Hard disk.
Once the Hard disk has been set up and partitioned and marked as bootable you can install Workbench. Workbench 2.0 and later has an Install disk with scripts to do this for you. For Workbench 1.3 you have to do this manually by copying the entire contents of the Workbench and Extras disk to your hard disk.

For example,
1. Open a Shell to get a command prompt
2. Insert the Workbench disk in DF0:
3. Type COPY DF0:#? To DH0: ALL CLONE which will copy all files from the floppy
in DF0: to the harddisk partition DH0:.
4. Remove the Workbench disk and insert the Extras disk
5. Type COPY DF0:#? To DH0: ALL CLONE to copy all the files to your hard disk.

For most application programs, except games, you can install them to your hard disk as well using a supplied install program or just by drag and dropping the files from
the disk into a new drawer (also known as a directory or folder) on your hard disk.

Adding more Memory to the A500:

The Amiga memory is split into Chip RAM (memory used by the custom chipset to store graphics and sound) and Fast RAM (memory which is used only by the Processor).
The Amiga A500 can come with 512K or 1M of memory. You can increase Chip RAM up to the maximum of 2Mb and Fast RAM up to 7Mb or 8Mb (depending if you have 1Mb or 2Mb of Chip RAM) to a total of 9Mb. You can increase RAM by adding memory via a new memory board into the expansion slot underneath the Amiga behind a trapdoor or via the Expansion Port on the left hand side, sometimes as part of another device such as the A590.
When increasing Chip RAM you must also upgrade the Agnus chip which is used to address the Chip RAM area to a new version that can handle 1M or 2Mb or Chip RAM.
See documentation with a board or device on how to install extra memory.

Upgrading the Processor:

The standard 68000 7MHz processor in the Amiga A500 is quite slow and cannot cope with later applications and games. The processor is slotted on the main mother board, the only direct pin-for-pin replacement is the 68010. For faster processors such as the 68020, 68030 or 68040 then a new expansion board needs to be purchased and inserted via the trapdoor expansion slot underneath the Amiga.


released March 30, 2015

Harleyquin Z. Jones appears courtesy of the balloonminati.



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Purple Johnson Blimp Situation Adelaide, Australia

Purple Johnson Blimp Situation.
Working with chaos and deterring
listeners since 2006.

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